What is CVE-2026-55248?

CVE-2026-55248 is a critical-severity uncontrolled resource consumption vulnerability in plone.app.portlets (pip), affecting versions >= 7.0.0, <= 7.0.1. It is fixed in 7.0.2, 6.0.4, 5.0.8. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.

How severe is CVE-2026-55248?

CVE-2026-55248 has a CVSS score of 9.1 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of plone.app.portlets are affected by CVE-2026-55248?

plone.app.portlets (pip) versions >= 7.0.0, <= 7.0.1 is affected.

Is there a fix for CVE-2026-55248?

Yes. CVE-2026-55248 is fixed in 7.0.2, 6.0.4, 5.0.8. Upgrade to this version or later.

Is CVE-2026-55248 exploitable, and should I be worried?

Whether CVE-2026-55248 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-55248 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-55248?

Upgrade: plone.app.portlets to 7.0.2 or later, plone.app.portlets to 6.0.4 or later, plone.app.portlets to 5.0.8 or later.

CVE-2026-55248 in plone.app.portlets

Q: How severe is CVE-2026-55248?

CVE-2026-55248 has a CVSS score of 9.1 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of plone.app.portlets are affected by CVE-2026-55248?

plone.app.portlets (pip) versions >= 7.0.0, <= 7.0.1 is affected.

Q: Is there a fix for CVE-2026-55248?

Yes. CVE-2026-55248 is fixed in 7.0.2, 6.0.4, 5.0.8. Upgrade to this version or later.

Q: Is CVE-2026-55248 exploitable, and should I be worried?

Whether CVE-2026-55248 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-55248 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-55248?

Upgrade: plone.app.portlets to 7.0.2 or later, plone.app.portlets to 6.0.4 or later, plone.app.portlets to 5.0.8 or later.

Summary

plone.app.portlets vulnerable to denial of service via RSS feed portlet

Workarounds

If upgrading is not immediately possible:

Restrict who can manage portlets: remove the plone.app.portlets.ManageOwnPortlets permission from untrusted roles, and limit Manage portlets to trusted administrators (usually this is already restricted to the Manager and Site Administrator roles).
Where the RSS portlet is not needed, unregister it so it cannot be added. This would need to be done by editing a portlets.xml in your own code, so it is not a quick fix.

References

This is similar to this plone.app.event vulnerability. It was discovered by the Plone Security Team by thinking of similar cases to the plone.app.event problem.

Impact

By adding an RSS portlet, and giving this a link to a very large file, a member can cause a denial of service attack, because Plone will use lots of memory. The member could also use different urls to try to get information about the internal network and open port numbers (SSRF). A malicious RSS feed could cause stored XSS, when the url of a feed item is a javascript url.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-55248 has a CVSS score of 9.1 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (7.0.2, 6.0.4, 5.0.8); upgrading removes the vulnerable code path.

Affected versions

plone.app.portlets (>= 7.0.0, <= 7.0.1) plone.app.portlets (>= 6.0.0, < 6.0.4) plone.app.portlets (< 5.0.8)

Security releases

plone.app.portlets → 7.0.2 (pip) plone.app.portlets → 6.0.4 (pip) plone.app.portlets → 5.0.8 (pip)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

The problem has been patched in plone.app.portlets.

For Plone 6.2: upgrade to plone.app.portlets 7.0.2
For Plone 6.1: upgrade to plone.app.portlets 6.0.4
For Plone 6.0: upgrade to plone.app.portlets 5.0.8

Frequently Asked Questions

What is CVE-2026-55248? CVE-2026-55248 is a critical-severity uncontrolled resource consumption vulnerability in plone.app.portlets (pip), affecting versions >= 7.0.0, <= 7.0.1. It is fixed in 7.0.2, 6.0.4, 5.0.8. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
How severe is CVE-2026-55248? CVE-2026-55248 has a CVSS score of 9.1 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of plone.app.portlets are affected by CVE-2026-55248? plone.app.portlets (pip) versions >= 7.0.0, <= 7.0.1 is affected.
Is there a fix for CVE-2026-55248? Yes. CVE-2026-55248 is fixed in 7.0.2, 6.0.4, 5.0.8. Upgrade to this version or later.
Is CVE-2026-55248 exploitable, and should I be worried? Whether CVE-2026-55248 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-55248 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-55248?
- Upgrade plone.app.portlets to 7.0.2 or later
- Upgrade plone.app.portlets to 6.0.4 or later
- Upgrade plone.app.portlets to 5.0.8 or later